Researchers in a study produced by the National Association of Criminal Defense Lawyers and the Santa Clara University Law School examined cases of criminal prosecutors withholding information helpful to the defense. Despite clear precedent that the information must be shared, judges reviewing the cases usually didn’t require corrective action.

Defense attorneys and wrongful convictions researchers have long said that such misconduct, known as a Brady violation, is common and have pushed “open files” policies requiring all court records to be made available. The mandate that prosecutors provide everything that could meaningfully help the defense dates back to a historic 1963 Supreme Court ruling, Brady V. Maryland.

The National Registry of Exonerations at the University of Michigan Law School has found that Brady violations have contributed to hundreds of wrongful convictions. One of the most famous involved the late Sen. Ted Stevens, who was accused of accepting a bribe and convicted of seven felonies. It later emerged that the Justice Department had withheld key exculpatory records, and the case against Stevens was dismissed.

But while researchers and lawyers point to these violations as one of the core factors contributing to wrongful convictions, they haven’t until this recent study had a good sense of how courts address the issue once it’s brought to the judge’s attention. They’re now in a better position to address two key questions: Is there a consistent standard for determining when a violation has occurred? How commonly does the judge order a new trial?

Researchers in the study reviewed 620 court rulings addressing Brady violation concerns, and found that in 145 of the cases the court record showed information would have been helpful to the defense had it been shared. But even then, judges were rarely moved to take action.

Only one seventh of the time -- 21 out of the 145 cases -- did a judge conclude that a significant error had occurred. The rest of the time, the judge ruled that the withheld evidence wasn’t important enough to have made a difference in the case’s outcome. In other words, they let the error slide.

Interestingly, judges had no clear standard for when they deemed that an undisclosed fact tipped the scales of justice. “Two courts could have the same favorable information before them in remarkably similar factual contexts and come out differently,” the study found.

It also found that some kinds of undisclosed information were more effective at getting the judge’s attention: They were more convinced a significant violation occurred when the information showed that a witness had received an incentive or deal to testify.

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